1. Field of the Invention
The present invention relates to acrylic fibers excellent in bulkiness and soft to the touch which are fitted for home furnishings and apparel and to a process for producing such acrylic fibers.
2. Discussion of the Background
In general, natural fur is provided with upright fibers each attenuated at the portion nearest to the root and at the tip portion, hence having a soft characteristic feel effect relatively to the average thickness of the fiber. On the other hand, a variety of man-made fur-like fabrics produced by using synthetic fibers have so far been on the market. However, since the used synthetic fibers of these products have each a uniform thickness throughout the length thereof, these products will have a rough and hard feel even if the used synthetic fibers are made equal in fineness to the fibers of natural fur. Thus, man-made fur-like products at present are not comparable at all in feeling to natural fur. There are proposed two methods (Japanese Patent Kokai (Laid Open Publn.) Nos. 16906/80 and 134272/81) as attempts to offset the above drawback of the fur-like products. One of the methods comprises preparing a fabric by using synthetic fibers, particularly polyester fibers, as pile, and immersing the tip portions of the pile fibers in an aqueous alkali solution to hydrolyze and attenuate the tip portions. The other method comprises immersing one-end portions of fiber bundles in a hydrolytic aqueous solution to sharpen the end portions.
Because of the immersion treatments with aqueous solutions of chemicals, both the methods have industrial problems in that the degree of attenuating the tip portions of the upright fibers is difficult to control, batchwise operations of the treatments are obliged, and the efficiency of the treatments is low. Application of the above methods to acrylic fibers is also in such a situation that limited solvents can be used industrially with ease and the recovery of the used solvents is difficult.
As regards the prior art relating to fibers having Y-type special cross sections, various shapes of fibers are proposed in documents, e.g. Japanese Patent Kokai (Laid-Open Publn.) No. 103311/80, but these fibers are unsatisfactory for achieving objects of the present invention.